I have mentioned the question of our own boats' experiences of depth-charges. A few instances of both English and German anti-submarine strafing may be of interest. At the beginning of the war the German depth-charge was a thing of contempt, and its English counterpart was nearly as useless. Submarines were sunk in those days by what might be called "accidental" methods. The boat either made a mistake and was then rammed or destroyed by gunfire, or else it met a mine or ran into nets. Depth-charges were not big enough to be dangerous, and it was not realised that even a big depth-charge must explode very close to the boat's hull before actual damage is caused. Moral effect is, of course, a different thing: there is a case of a U-boat surrendering as a result of one rivet having been knocked out of her hull by a comparatively distant explosion. That, of course, is a matter of personnel; and the depth-charges we used often had a remarkable effect, although no structural damage whatever had been caused by them. When our big depth-charges were first supplied, patrol boats and destroyers carried but few of them and were expected to be sparing in their use--in fact, they were not supposed to use them unless a fair chance was seen of an almost direct hit. Later, in 1917, the supply exceeded the demand--at least the demand on the previous scale--and anti-submarine vessels were supplied with just as many as they could comfortably stow on their decks; while orders were issued that any patch of water in which there was the faintest possibility or suspicion of a U-boat being present was to be sprinkled with depth-charges until there was no possibility of anything intact remaining in range. It is a feature of life in submarines that one always gives the hunters credit for seeing more than they do see: one watches a Zeppelin through the periscope--a Zeppelin cruising at perhaps five miles' range away--and one feels a sort of shrinking and an inclination to slip down to ninety feet or so for a spell in the certainty that one's periscope must have been seen. Of course it hasn't, and it probably won't be. One meets a dark shape at night, and one does a "crash dive" at once, heaving a sigh of relief as one sees the gauge show sixty feet. One forgets that a submarine, besides being a much smaller mark to see at night, keeps in all probability a far better look-out than any other class of vessel. In the same way, the explosion of a depth-charge usually sounds closer than it is, and the submarine officer is inclined to jump to the conclusion that it is directly aimed at him or at some indication of his wake. As a matter of fact it is more probably aimed at an oil-patch or a piece of drift-wood some half-mile off, and the ship dropping it has no real knowledge of the submarine's proximity at all.